system-familyVarianLinear Accelerator

Varian Clinac iX Family

The highest-volume legacy C-arm linear accelerator platform in global radiation oncology. Clinac iX deployed broadly across community and academic departments for a decade — 2004 through 2014 — before TrueBeam took over as Varian's flagship. A large share of the world's currently operating radiation-therapy linacs are Clinac iX systems, and the platform remains a critical service and refurb topic for the field.

Variants (dedicated System Cards)

  • Clinac iX 6+15 MV — dual-energy 6 MV / 15 MV photon configuration; 6 / 9 / 12 / 15 MeV electrons. General radiotherapy workhorse.
  • Clinac iX 6+18 MV — 6 MV / 18 MV photons with the higher-energy electron suite up to 22 MeV. Favored for deep-seated and bulky disease.

Shared platform

  • Dose rate — 600 MU/min standard; 800 MU/min in SRS mode on upgrade-configured units.
  • Millennium MLC — 80-leaf or 120-leaf multileaf collimator. Millennium 120 is the workhorse IMRT / VMAT MLC (0.5 cm inner leaf width for the central 20 cm).
  • On-Board Imager (OBI) — kV imaging arm supports orthogonal kV-kV, planar kV, CBCT, and kV fluoro.
  • Cone-Beam CT (CBCT) — kV CBCT on the OBI for IGRT; image quality is serviceable for soft-tissue IGRT but behind current TrueBeam / Halcyon iterations.
  • Delivery modes — 3D-CRT, IMRT, RapidArc (VMAT), IGRT, SRS, SBRT.
  • Mechanics — 100 cm SID, gantry rotation ±185°, Exact IGRT couch, Exact arm.
  • PortalVision MV imaging — MV portal imager for EPID-based verification.

RF chain and klystron / waveguide specifics

  • Klystron-based RF on most iX production. Thyratron switching, SF6-insulated waveguide.
  • Klystron end-of-life is the dominant service-capex event on Clinac iX — planning for klystron replacement is a standing budget item.
  • Waveguide vacuum discipline — pressure and arcing history is a service-history metric worth tracking across the machine's life.
  • Magnetron vs klystron variants existed earlier in the Clinac line; iX-era production is predominantly klystron.

Shared install considerations

  • Dedicated shielded vault — lead and concrete shielding designed per the machine's MV energies and workload.
  • 3-phase 480 V, ~200 kVA power; chilled water supply for RF cooling.
  • State radiation license + Qualified Medical Physicist (QMP) + RSO mandatory.
  • TG-142 commissioning and periodic QA per AAPM TG-142 and facility policy (see TG-142).

Market position and life-cycle

  • Installed base — one of the largest active linac populations worldwide as of the current decade.
  • TrueBeam upgrade vs Clinac iX refurb — a standing capital conversation. Clinac iX does not field-upgrade to TrueBeam; the chassis, control system, and RF stand are materially different. Continued iX operation is economically viable at many centers provided klystron / waveguide / thyratron service is disciplined.
  • Service ecosystem — mature, with broad OEM and multi-vendor service coverage.

Shared field guide

Klystron end-of-life, waveguide vacuum and arcing, MLC leaf service, thyratron replacement cadence, interlock discipline, MLC calibration, dose rate constancy, flatness/symmetry drift, OBI kV-arm service — see Clinac iX Field Guide.

Parts

Related

Cross-layer references